1. Field of the Invention
The present invention relates to a phase control method and a phase control device for phase controlling an alternating current (AC) power supply, and controlling the power to a load.
2. Description of the Related Art
Conventionally, phase control of controlling the phase angle at which the AC current flows and adjusting the power is adopted in the case of the AC load to control the power to the load such as a heater, and such phase control has an advantage of excelling in response of the control since power to the load is controlled by controlling the phase angle of a switching element for every half cycle of a power supply frequency (refer to, for example, Japanese Patent Application Laid-Open No. 06-282337).